docs: def place_data_on_block_device(blk_device, data_src_dst):
      """Migrate data in data_src_dst to blk_device and then remount."""
      # mount block device into /mnt
      mount(blk_device, '/mnt')
      # copy data to /mnt
      copy_files(data_src_dst, '/mnt')
      # umount block device
      umount('/mnt')
      # Grab user/group ID's from original source
      _dir = os.stat(data_src_dst)
      uid = _dir.st_uid
      gid = _dir.st_gid
      # re-mount where the data should originally be
      # TODO: persist is currently a NO-OP in core.host
      mount(blk_device, data_src_dst, persist=True)
      # ensure original ownership of new mount.
      os.chown(data_src_dst, uid, gid)